1. Technical Field
This invention relates to a sealing arrangement such as may be used to seal around a shaft extending between units in a power train for delivering power to a functional mechanism of a mining machine.
2. Background Information
In a power train for driving a functional mechanism such as the cutting head, conveyor, loading mechanism, tram or other operation performing part of a mining machine, it is important that the drive connection between adjacent units in the train be adequately sealed to prevent contamination of the lubricant used in protecting the various wear surfaces within the units. The conditions under which mining machines inherently operate are particularly harsh in creating particles that may infiltrate and contaminate the lubricant normally protecting machine parts against wear.
Also, in the design of such power trains, space and strength considerations dictate that the various units in the power train be arranged compactly with a limited amount of space between adjacent units. This dictates the use of special design features or service procedures for servicing the units or in providing routine maintenance or replacement of the various units in the power train. In one prior power train arrangement for example, a split rubber seal is utilized between an electric drive motor and a gearbox to cover a drive shaft connected between the motor and the gears in the gearbox. The seal comprises two half torics sections split in an axial direction and sealingly clamped together between inside and outside half cylindrical metal liners. When unclamped, the liners and seal halves may be removed from between the motor and gearbox for servicing either the motor or the gearbox from the space therebetween or for utilization of the space in removing either of such units.
Another prior arrangement utilizes a solid annular rubber seal clamped between the motor and the gearbox within a pilot bore supporting the motor on the frame of the mining machine. With this arrangement, disassembly of the motor is required for access to the seal or the gearbox.
Disclosed in U.S. Pat. No. 3,415,285 is a more complex form of sealing arrangement used in an environment different than that within which the present invention is used. U.S. Pat. No. 3,415,285 teaches the use of a packing gland between two relatively fixed tube end members which are part of a conduit such as may be used for transporting liquid. The gland is fitted into the end of one of the tube members and is retractable in such member to allow a blind flange to be inserted between the tube ends to close off flow through the conduit without having to move the tube ends. Impervious sealing is provided between the gland and the tube end by a rubber collar having one flanged end clamped sealingly to the gland and an opposite flanged end clamped sealingly within the tube end. A travel screw arrangement acting between the gland and the one tube member is used to move the gland axially within the tube for changing out the blind flange. Additionally, bolts are connected between the two fixed tube end members to insure axial alignment of the two members.